Interlock sewing machines



eb. 25, 1969 N. GORIN ETAL 3,429,275

INTERLOCK SEWING MACHINES Filed 001.. 24, 1965 Sheet of e INVENTORS NATHAN A GOR/N, RAYMOND GOR/N,

AND

SAUL G-OR IN ATTORNEYS Feb. 25, 1969 N. GORIN ETAL INTERLOCK SEWING MACHINES Sheet LofG Filed Oct. 24, 1965 NATHAN GORIN,

RAYMOND GOR AND SAUL GORIN ATTUR/VS Feb. 25, 1969 N. GORIN ETAL 3,429,275

INTERLOCK SEWING MACHINES Filed Oct. 24, 1965 Sheet 3 of e INVENTORS NATHAN 60R RAYMOND 60R I AND SAUL GORIN Feb. 25, 169 N. GORIN ETAL INTERLOCK SEWING MACHINES Sheet 4 of Filed Oct. 24, 1965 INVENTO S mm RR 0 6w NMM oA H L m u M M GOR/N Feb. 25, 1969 N. GORIN ETAL 3,429,275

INTERLOCK SEWI NG MACHINES Filed Oct. 24, 1965 Sheet 5 of INVENTOPS NATHAN Gee/N RAYMOND gem/v FRED BURGER? BY-' $401. oa/1v mywh,

A TTU/FA/EYS.

Feb. 25, i969 NGORIN ETAL INTERLOCK SEWING MACHINES Sheet Filed 001;. 24, 1965 NATH/l/V GOR/N, RAYMOND GORIN,

JHUL G-OR/N WW ATTURNEYH flnited tates 3,429,275 INTERLOCK SEWING MACHINES Nathan Gorin, Long Beach, Raymond Gorin, Massapequa Park, and Saul Gorin, Flushing, N.Y., assignors to N. Gorin 8: Sons, Inc., New York, N.Y.

Fiied Oct. 24, 1965, Ser. No. 504,584 US. Cl. 112168 Int. Cl. D051) I/J4, 35/08, 1/06 4 Claims ABSTRACT OF THE DISCLOSURE This invention relates generally to sewing machines. More specifically it relates to a chain lock stitch or interlock stitch sewing machine mechanisms.

It is generally well known to those skilled in the sewing machine and garment manufacturing industries that vast numbers of old lock stitch machines are used in the trade, although the machines are no longer manufactured. These machines include bobbins within their bases from which thread is dispensed to the looper within the base. In view of the fact that the bobbin can hold only a relatively limited amount of thread thereupon, it is necessary (particularly in garment manufacture where the machine works quite steadily) to stop production in order to remove the bobbin, rewind additional thread thereupon and return the loaded bobbin into the machine. This stoppage of production is obviously costly and accordingly undesirable.

Accordingly it is a principal object of the present invention to provide a conversion unit for a lock stitch sewing machine which will convert it to a chain lock stitch or interlock stitch machine to eliminate the necessity of employing a bob-bin and thus eliminate its attendant above described shortcoming.

Another object is to provide a conversion unit which will change a lock stitch sewing machine to a bobbinless chain lock or interlock stitch sewing machine.

Still another object is to provide a bobbinless two thread chain lock stitch or interlock stitch sewing machine which will produce a #401 interlock stitch (Universal Standard Classification).

Yet another object is to provide a sewing machine wherein thread is fed a secondary thread from a spool directly to a looper in the base.

Other objects are to provide a conversion unit for a lock stitch machine for changing the machine to a bobbinless interlock stitch sewing machine wherein the conversion unit is simple in design, inexpensive to manufacture, rugged in construction, easy to install and efficient in operation.

These and other objects will be readily apparent upon a study of the following specification and the accompanying drawings wherein:

FIGURE 1 is a perspective view of a sewing machine incorporating the present invention, and illustrating in particular the thread being fed into the machine,

FIG. 2 is a fragmentary perspective view of the terminal end of the thread fed into the machine base and illustrating its association with the machine,

FIG. 3 is a cross sectional view taken on line 33 of FIG. 1,

atent FIG. 4 is cross sectional view taken on line 44 of FIG. 1,

FIG. 5 is a cross sectional view taken on line 5-5 of FIG. 4,

FIG. 6 is a cross sectional view taken on line 66 of FIG. 4,

FIG. 7 is a view as viewed on line 77 of FIG. 6,

FIG. 8 is a cross sectional view taken on line 88 of FIG. 7,

FIG. 9 is a fragmentary perspective view of the spreader reciprocating mechanism,

FIG. 10 is a bottom view of the spreader unit as viewed on line 1010 of FIG. 9,

FIG. 11 is a perspective view of the needle and looper shown in one particular relationship during the machine operation cycle, and showing in phantom line a subsequent position, and

FIG. 12 is a similar view showing further subsequent relative positions thereof.

FIG. 13 is an end elevational view as viewed on line 13-13 of FIG. 4.

FIG. 14 is a cross-sectional view taken on line 1414 of FIG. 13.

FIG. 15 is a cross-sectional view taken on line 15-15 of FIG. 13.

FIG. 16 is an exploded view of certain parts shown in FIG. 14, and

FIG. 17 is a side view of the pusher type feed unit.

Referring now to the drawings in detail, the numeral 20 represents a conversion unit for changing a lock stitch sewing machine to a bobbinless interlock stitch sewing I machine which is installed in a machine head 21.

The head 21 is comprised of a base 22 and an arm 23 mounted upon the base.

The conversion unit includes a longitudinal straight main shaft 24 supported in bearings 25 on the arm. A pulley 26 rigidly secured to one end of the shaft receives a motor driven endless belt 27 for delivering rotational movement to the shaft. The shaft provides means at its opposite end for vertically driving a conventional needle bar mechanism (not shown).

A timing gear 28 rigidly affixed to shaft 24 receives an endless timing belt 29 passing around a timing gear 30 rigidly secured to a rotatable shaft 31 within the base. Shaft 31 is supported in bearing blocks 32 and 33 secured to the underside 34 of the base.

A bevel gear 35 aifixed on rotatable shaft 31 is engaged with a bevel gear 36 on a vertical cam shaft 37, supported in bearings 38 on the block 32. The cam shaft has an eccentric 39 about which a pair of bearing blocks 40 are positioned. The bearing blocks 40 are supported within a yoke 41 havings arms 42a and 42b between which the blocks 40 are transversely slidable. The yoke is supported longitudinally slidable between surfaces 43 and 44 on the block 32.

A longitudinal reciprocating shaft 45 is held at one end in the yoke by means of set screw 46 engaged in a circumferential groove 47 which permits the shaft to rotate relative to the yoke but held in a longitudinal direction relative thereto. A cam 48 secured by a set screw 49 on shaft 31 provides movement to a lever arm 50 carrying cam 48 within one end of the lever. The opposite end of lever arm 50 is pivotally attached by means of a stud 51 to one end of a second lever arm 52. The opposite end of lever arm 52 is rigidly secured by means of a set screw 53 to the shaft 45. Thus reciprocating motion is transferred to shaft 45.

A block 54 is also secured to shaft 45 and a looper 55 is secured by means of set screw 56 to the block 54.

The opposite end of shaft 45 is supported in a bearing 57 on the base.

A spreader unit 58 driven by shaft includes block 59 mounted by means of set screw 60 on shaft 45. A circumferential groove 61 on block 59 receives the bifurcated end 62 of a lever 63 centrally pivoted on a cross shaft 64 supported on a block 65 on the underside of the base. The opposite end of lever 63 has a pair of converging jaws 66 between which a downward bent tab 67 of a slidable spreader 68 is received.

The spreader is slidably secured by means of blocks 69 on the underside of a plate 70. A hook 71 on the spreader moves relative to an opening 72 through the plate and through which a needle 73 secured to a needle bar 74 passes during stitching operation.

In operative use, rotational movement is carried from the main shaft to the shaft 31 by means of the timing gears and timing belt. Longitudinal reciprocating movement is delivered to shaft 45 by means of the cam shaft driven from shaft 31. Reciprocating rotational movement is delivered to shaft 45 by the cam 48 and associated lever 50 and 52. Thus during each rotation of shaft 31 the looper 55 moves through a generally elliptical path due to the rotational and longitudinal movements of shaft 45. During this travel of the looper it moves from the position shown by solid lines in FIG. 11 to the position shown by solid lines in FIG. 12. The complete cycle is shown in FIGS. 12A to 12E. During this cycle the needle 73 moves vertically relative thereto so that loops formed in thread 75 of the looper are engaged with thread 76 of the needle to form a continuation of stitches.

While the timing of the relative positions of the looper and needle may vary considerably due to the kind of material being stitched, and material thickness it may be generally stated that (as shown in FIGS. 11 and 12) as the looper pivots rearward the needle descends. As the needle ascends the looper pivots forwardly and approximately at the same time travels in a longitudinal direction toward the left. Thus the looper arrives on the opposite side of the needle during the above cycle to perform various looping of the threads to produce a conventional interlock stitch.

As shown in FIG. 1, the thread 75 is fed from a spool 77 on a spool rack 78. The thread passes through a tension device 79 then through a channel 80 on the upper side 81 of the base, then through an opening 82 in the base to the looper.

A hinged plate 83 covers the channel 80. Various eyelets 84 guide the thread as it changes travel directions.

The thread 76 is fed from a spool 85 on the spool rack, through a tension device 86, various eyelets 87 and to the needle.

In the present device the reciprocating shaft 45 travels longitudinally approximately one quarter of an inch and it rotates approximately thirty degrees.

Thus a conversion unit has been shown which would replace certain of the equivalent parts in an old lock stitch machine and convert the same into a bobbinless interlock stitch machine.

The present invention includes a material feeding mechanism 90 having self-contained means for controlling the rate of material fed under the needle. More specifically it regulates the amount of material fed into each pleat by increasing or decreasing the amount thereof being fed in proportion to the stitching rate of the needle or needles.

The feeding mechanism 90 includes a take off mechanism 91 that transfers rotational movement from the mainshaft 24 into a reciprocating arcuate movement that is delivered to a pusher type feed unit 92.

The take off mechanism 91 as best shown in FIGS. 13 to 17 comprises a hub 93 rotationally adjustably secured to the pulley 26 and wherein a pair of screws 94 pass through arcuate slots 95 in the hub and are secured in threaded openings 96 in the pulley.

The hub 93 has a transverse slot 97 therein extending across the hub center and a crankpin assembly 98 is movable therein in a radial direction relative to the hub. A screw 99 is engaged in threaded opening 100 in the crankpin providing radial adjustment means for the crankpin. The screw 99 has an undercut 101 for being received Within a notch 102 of a plate 103 secured by screws 104 to the hub, thereby providing a structure for retaining the crankpin in stationary longitudinal direction yet allowing rotation thereof.

One end of a push rod assembly 105 is provided with an opening 106 for receiving crankpin 98 and the opposite end of the assembly 105 is connected to an arcuate arm 107 which in turn is mounted on a shaft 108. The assembly 105 is comprised of a pair of members 109 and 110 threadingly secured together as shown at 111 for providing longitudinal adjustment thereof between the arm 107 and crankpin 99.

The arm 107 is of arcuate configuration having a slot 112 for receiving a thumb screw 113 carried by the push rod assembly. The slot 112 extends in a generally radial direction for adjustment of the amount of arcuate movement transmitted to shaft 103.

The shaft 108 is supported rotationally free in bearing blocks 114 and 115 mounted upon the side of the sewing machine head arm 23.

A lever 116 is secured at its one end to the shaft 108; the other end of the lever carrying the pusher type feed unit 92. The feed unit includes a pair of pusher elements 117 and 118 shown in FIG. 17 which alternately push material under the pressure foot 119 secured to the pressure foot bar 120.

In the operative use, as the shaft 24 rotates the eccentrically positioned crankpin 98 delivers throw movement to the push rod 105 thus causing arm 107 to transmit arcuate movement to the shaft 108 and to lever 116 secured thereto. This causes the pusher elements to alternately push the material under the pressure foot. By adjusting the various parts the amount of material feed can be altered as desired.

While various changes may be made in the detail construction, it is understood that such changes will be in the spirit and scope of the present invention as is defined by the appended claims.

What is claimed is:

1. In an interlock sewing machine, the combination of a sewing machine head, a base, and an arm mounted by said base, a longitudinally reciprocating and rotationally reciprocating shaft, having a yoke on one end thereof, drive means for said shaft, means supporting said shaft within said base of said sewing machine head, a looper block, means securing said looper block to said shaft, a looper, means securing said looper to said block and means for feeding a thread from a remotely located spool to said looper, wherein said drive means comprises a straight main shaft, said main shaft being supported in said arm of said head, a pulley on said main shaft, a motor driven belt over said pulley supplying a source of rotational drive to said main shaft, a timing gear on said main shaft, a timing belt over said timing gear, a second timing gear on said rotating shaft within said base, a timing belt over said timing gears, a longitudinally reciprocating mechanism and a rotationally reciprocating mechanism engaged with said rotating shaft, wherein said longitudinally reciprocating mechanism comprises a first bevel gear on said rotating shaft, a cam shaft, means mounting said cam shaft within said base, a second bevel gear engaged with said first bevel gear, said second bevel gearbeing affixed on said cam shaft, said cam shaft having an eccentric, a pair of bearing blocks around said eccentric, said bearing blocks being held transversely slidably free in said yoke, said reciprocating shaft having a circumferential groove near said end and said yoke carrying a set screw received within said groove to permit rotational movement of said reciprocating shaft but arrest longitudinal movement thereof relative to said yoke.

2. In an interlock sewing machine, the combination as set forth in claim 1, including a spreader unit, said spreader unit comprising a block mounted on said reciprocating shaft, a circumferential groove on said block, a centrally pivotable lever operable by said shaft, a bifurcated end of said centrally pivotable lever operable within said groove, the opposite end of said lever having a pair of converging jaws, a slidable spreader having a tab receivable between said jaws, a plate flush on the upper side with the upper side of said base, said spreader being held slidably free on the underside of said plate, said plate having an opening therethrough for admitting a needle of said arm needle bar therethrough, a hook on said spreader adjacent said opening, said looper being located adjacent said hook.

3. In an interlock sewing machine, the combination as set forth in claim 2, wherein said base has a groove in the upper side thereof for receiving thread from a spool to said looper, a hinged cover over said groove, the upper side of said cover being flush with the upper side of said base and having an opening at one end of said groove through said base to feed said thread from said groove to said looper.

4. In an interlock sewing machine, the combination as set forth in claim 3, wherein there is additionally a material feeding mechanism, comprising a hub rotationally adjustably secured to said pulley on said main shaft, an adjustable push rod secured at one end to said crankpin and secured at its other end to an arm of a feed mechanism shaft supported in bearings on one side of said head arm, a lever secured to said feed mechanism shaft and a pusher type feed unit secured to said lever for pushing materials under a pressure foot during stitching Operation.

References Cited JAMES R. BOLER, Primary Examiner.

US. Cl. X.R. 112134, 200 

